GM/CHEVROLET HORSEPOWER AND TORQUE CURVES
If you study the performance curves below you will see two major benefits of GearSplitting. As
an example we'll use the TH400 or 4L80E trans chart with a Vortec 7.4 (454). Gears are multipliers
of torque so at 3,000 rpm in 2ndover the torque multiplier is 4.73 where without the GEAR
VENDORS you would get into 2500rpm in 3rddirect at 4.10. The difference in engine torque is
only 10lbs ft. but the difference in the multiplier 4.73 vs 4.10. That's over 18% more working
torque.
At this same moment horsepower at 3,000rpm is 260 instead of 210 @ 2500 which
is over 23% more horsepower with all the reliability of your stock powerplant. To figure the drop
in rpm or torque multiplier from on gear to the next calculate as follows: Final Drive Ratio of
the gear you are shifting to, divided by the gear you are shifting from, minus 1, times 100. The
difference from 1stover to 2nd is even more dramatic. This is why if you are towing or loaded
heavily, the best way to reliably improve performance is with the GEAR VENDORS UNDER/OVERDRIVE™.
It's the same reason the big 18 wheelers have 2 and 3 speed auxiliaries for 10 to 15 or more gears.
Click on graphs to enlarge.
GM 5.7L (LOS)

GM 6.2 V8 (Diesel (LH6)

GM 6.5 V8 Diesel (L65)

GM 7.4L (L19) 
GM 5.7L Vortec (L31) 
GM 7.4L Vortec (L29) 
GEAR VENDORS, INC. 1717 North Magnolia Avenue, El Cajon, CA 92020
Toll Free 8009999555 • Telephone (619) 5620060 • Fax (619) 5621186
